Department of Occupational and Environmental Health PublicationsCopyright (c) 2015 University of Iowa All rights reserved.http://ir.uiowa.edu/oeh_pubs
Recent documents in Department of Occupational and Environmental Health Publicationsen-usSun, 01 Mar 2015 01:32:08 PST3600Cytotoxic activity of triazole-containing alkyl β-D-glucopyranosides on a human T-cell leukemia cell linehttp://ir.uiowa.edu/oeh_pubs/191
http://ir.uiowa.edu/oeh_pubs/191Fri, 27 Feb 2015 06:38:09 PST
Background: Simple glycoside surfactants represent a class of chemicals that are produced from renewable raw materials. They are considered to be environmentally safe and, therefore, are increasingly used as pharmaceuticals, detergents, and personal care products. Although they display low to moderate toxicity in cells in culture, the underlying mechanisms of surfactant-mediated cytotoxicity are poorly investigated.

Results: We synthesized a series of triazole-linked (fluoro)alkyl β-glucopyranosides using the copper-catalyzed azide-alkyne reaction, one of many popular “click” reactions that enable efficient preparation of structurally diverse compounds, and investigate the toxicity of this novel class of surfactant in the Jurkat cell line. Similar to other carbohydrate surfactants, the cytotoxicity of the triazole-linked alkyl β-glucopyranosides was low, with IC50 values decreasing from 1198 to 24 μM as the hydrophobic tail length increased from 8 to 16 carbons. The two alkyl β-glucopyranosides with the longest hydrophobic tails caused apoptosis by mechanisms involving mitochondrial depolarization and caspase-3 activation.

Conclusions: Triazole-linked, glucose-based surfactants 4a-g and other carbohydrate surfactants may cause apoptosis, and not necrosis, at low micromolar concentrations via induction of the intrinsic apoptotic cascade; however, additional studies are needed to fully explore the molecular mechanisms of their toxicity.

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Edward Davis Oldham et al.Chlorpyrifos Exposure and Respiratory Health among Adolescent Agricultural Workershttp://ir.uiowa.edu/oeh_pubs/190
http://ir.uiowa.edu/oeh_pubs/190Fri, 27 Feb 2015 06:38:08 PST
Chlorpyrifos (CPF) is a commonly used organophosphate insecticide (OP). In adults, exposure to OPs has been inconsistently associated with reduced lung function. OP exposure and lung function has not been assessed in adolescents. The objective of this study was to assess CPF exposure and lung function among Egyptian adolescents. We conducted a 10-month study of male adolescent pesticide applicators (n = 38) and non-applicators of similar age (n = 24). Urinary 3,5,6-trichloro-2-pyridinol (TPCy), a CPF-specific metabolite, was analyzed in specimens collected throughout the study. Spirometry was performed twice after pesticide application: day 146, when TCPy levels were elevated and day 269, when TCPy levels were near baseline. Applicators had higher levels of TCPy (mean cumulative TCPy day 146 = 33,217.6; standard deviation (SD) = 49,179.3) than non-applicators (mean cumulative TCPy day 146 = 3290.8; SD = 3994.9). Compared with non-applicators, applicators had higher odds of reporting wheeze, odds ratio = 3.41 (95% CI: 0.70; 17.41). Cumulative urinary TCPy was inversely associated with spirometric measurements at day 146, but not at day 269. Although generally non-significant, results were consistent with an inverse association between exposure to CPF and lung function.
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Catherine Callahan et al.Toxicology testing in fatally injured workers: a review of five years of Iowa FACE cases.http://ir.uiowa.edu/oeh_pubs/189
http://ir.uiowa.edu/oeh_pubs/189Thu, 19 Feb 2015 14:53:02 PST
Toxicology testing of fatally injured workers is not routinely conducted. We completed a case-series study of 2005-2009 occupational fatalities captured by Iowa's Fatality Assessment and Control Evaluation (FACE) Program. The goals of our research were to: (1) measure the proportion of FACE cases that undergo toxicology testing, and describe the factors associated with being tested, and (2) measure the rate of positive toxicology tests, the substances identified and the demographics and occupations of victims who tested positive. Case documents and toxicology laboratory reports were reviewed. There were 427 occupational deaths from 2005 to 2009. Only 69% underwent toxicology testing. Younger workers had greater odds of being tested. Among occupational groups, workers in farming, fishing and forestry had half the odds of being tested compared to other occupational groups. Of the 280 cases with toxicology tests completed, 22% (n = 61) were found to have positive toxicology testing. Commonly identified drug classes included cannabinoids and alcohols. Based on the small number of positive tests, older victims (65+ years) tested positive more frequently than younger workers. Management, business, science, arts, service and sales/office workers had proportionately more positive toxicology tests (almost 30%) compared with other workers (18-22%). These results identify an area in need of further research efforts and a potential target for injury prevention strategies.
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Marizen Ramirez et al.Accidents, OccupationalDemographyForensic ToxicologyHumansIowaOccupationsProgram EvaluationListen protect connect for traumatized schoolchildren: a pilot study of psychological first aid.http://ir.uiowa.edu/oeh_pubs/188
http://ir.uiowa.edu/oeh_pubs/188Tue, 17 Feb 2015 10:34:54 PST
BACKGROUND: Listen Protect Connect (LPC), a school-based program of Psychological First Aid delivered by non-mental health professionals, is intended to support trauma-exposed children. Our objective was to implement LPC in a school setting and assess the effectiveness of LPC on improving psychosocial outcomes associated with trauma.

METHODS: A pilot quasi-experiment was conducted with middle school children self-identified or referred to the school nurse as potentially exposed to stressful life experiences. LPC was provided to students by the school nurse, and questionnaires were administered at baseline, 2-, 4- and 8-weeks to assess life stressors, symptoms of post-traumatic stress disorder and depression, social support, and school connectedness. A total of 71 measurements were collected from 20 children in all. Although a small sample size, multiple measurements allowed for multivariable mixed effects models to analyze changes in the repeated outcomes over time.

RESULTS: Students who received the intervention had reduced depressive and posttraumatic stress symptoms from baseline throughout follow-up period. Total social support also increased significantly from baseline through 8-weeks, and school connectedness increased up to 4-weeks post-intervention.

CONCLUSIONS: This study demonstrates the potential of LPC as a school-based intervention of Psychological First Aid. Future randomized trials of LPC are needed, however.

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Marizen Ramirez et al.AdolescentAdultAntineoplastic AgentsChronic DiseaseFemaleHumansMaleMiddle AgedPsoriasisTime FactorsLongitudinal assessment of chlorpyrifos exposure and self-reported neurological symptoms in adolescent pesticide applicatorshttp://ir.uiowa.edu/oeh_pubs/186
http://ir.uiowa.edu/oeh_pubs/186Wed, 04 Feb 2015 06:08:18 PST
Objectives Occupational exposure of organophosphorus pesticides, such as chlorpyrifos (CPF), in adolescents is of particular concern because of the potential vulnerability of the developing neurological system. The objectives of this study were to examine how neurological symptoms reported over the application season vary across time, whether these effects are reversible postapplication and if there are associations between CPF biomarkers and neurological symptoms in an adolescent study population. Setting The longitudinal study was conducted in two agricultural districts of Menoufia Governorate, Egypt between April 2010 and January 2011. Participants Male adolescent participants, including CPF applicators (n=57) and non-applicators (n=38), were recruited. Primary and secondary outcome measures Self-reported data for 25 neurological symptoms were collected at 32 time points over the 8-month period before, during and after the application season. Additionally, urine and blood samples were collected to measure urine trichloro-2-pyridinol (TCPy), a CPF-specific biomarker and blood cholinesterase activity. Results Applicators and non-applicators report the highest numbers of symptoms during the application season, followed by a reduction in symptoms after the application ended. Applicators reported a greater percentage of neurological symptoms, relative to baseline, than non-applicators after accounting for potential covariates. Among the applicators, cumulative TCPy was positively and significantly associated with the average percentage of symptoms (B=4.56, 95% CI 3.29 to 5.84; p
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Khalid Khan et al.The Future of Rural Water Supplies: Health and Infrastructure Policy Issues Workshophttp://ir.uiowa.edu/oeh_pubs/185
http://ir.uiowa.edu/oeh_pubs/185Thu, 15 Aug 2013 09:48:58 PDTDavid OsterbergIGWA Forum Question/Answer on Risk Analysis justification of Limited Remediationhttp://ir.uiowa.edu/oeh_pubs/184
http://ir.uiowa.edu/oeh_pubs/184Thu, 15 Aug 2013 09:48:56 PDTDavid Osterberg et al.Effects of Restricted Knee Flexion and Walking Speed on the Vertical Ground Force Reaction During Gaithttp://ir.uiowa.edu/oeh_pubs/182
http://ir.uiowa.edu/oeh_pubs/182Fri, 05 Jul 2013 11:34:28 PDT
Although lower extremity immobilization, including restricted knee flexion, is commonly used in rehabilitation, the effect of angle of knee restriction and walking speed on the vertical ground reaction forces during gait is unclear. Force plate measurements were made on 36 healthy males walking at 3 different speeds when knee flexion was unrestricted and restricted to both 10 and 25°. Analysis of variance and post hoc analyses showed significant increases in 4 characteristics of the vertical ground reaction force in the restricted leg and in 2 characteristics in the unrestricted leg during walking with restricted knee flexion. Loading rate and unloading rate for the restricted leg and peak force for both legs showed significant speed-knee flexion restriction interactions. At the fast walking speed, 2 significant differences were found between knee flexion restrictions of 10 and 25°. The clinical implications of these findings are that restricted knee flexion during gait may significantly alter the forces applied to both lower limbs.
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Thomas M. Cook et al.Translations of the Humerus in Persons with Shoulder Impingement Symptomshttp://ir.uiowa.edu/oeh_pubs/181
http://ir.uiowa.edu/oeh_pubs/181Fri, 05 Jul 2013 10:59:32 PDT
Study Design: Two-group mixed-model analysis of covariance and correlation analysis. Objectives: To determine whether differences in humeral translations exist between patients with shoulder impingement symptoms and an asymptomatic comparison group, and if so, to determine if shoulder range-of-motion (ROM) measures are associated with abnormal translations. Background: Abnormal translations of the humeral head are believed to reduce the available subacromial space and to contribute to the development or progression of shoulder impingement symptoms. These abnormal translations have also been theorized to be related to tightness of the posterior capsule and decreased shoulder ROM. Methods and Measures: Three-dimensional humeral translations were tracked in symptomatic construction workers and an asymptomatic comparison group while elevating the arm in the scapular plane under no-load, 2.3-kg, and 4.6-kg hand-load conditions. Between-group comparisons were made across 3 phases of motion (30°–60°, 60°–90°, and 90°–120°) and the association between humeral translations and cross-body adduction and shoulder internal rotation ROM measures were determined by Pearson correlation analysis. Results: Persons with shoulder symptoms demonstrated small but significant changes in anterior-posterior translations of the humerus. These changes for the 90°–120° phase of humeral elevation were moderately negatively associated with available cross-body adduction ROM. Conclusions: The identified kinematic deviations are consistent with possible reductions of the subacromial space. Further study of relationships between posterior capsule tightness, rotator cuff function, and abnormal humeral translations is warranted to better delineate underlying kinematic mechanisms that may contribute to shoulder impingement symptoms and to refine rehabilitation techniques.
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Paula M. Ludewig et al.Three-Dimensional Scapular Orientation and Muscle Activity at Selected Positions of Humeral Elevationhttp://ir.uiowa.edu/oeh_pubs/180
http://ir.uiowa.edu/oeh_pubs/180Fri, 05 Jul 2013 09:25:02 PDT
Abnormal scapular kinematics and associated muscle function presumably contribute to shoulder pain and pathology. An understanding of scapular kinematic and electromyographic profiles in asymptomatic individuals can provide a basis for evaluation of pathology. The purpose of this study was to describe normal 3-dimensional scapular orientation and associated muscle activity during humeral elevation. Twenty-five asymptomatic subjects, 19-37 years old, were evaluated. Digitized coordinate data and surface electromyographic signals from the trapezius (upper and lower), levator scapulae, and serratus anterior were collected at static positions of 0°, 90°, and 140° of humeral elevation in the scapular plane. The scapula demonstrated a pattern of progressive upward rotation, decreased internal rotation, and movement from an anteriorly to a posteriorly tipped position as humeral elevation angle increased. Electromyographic activity of all muscles studied increased with increased humeral elevation angles. Differences between mean values at all elevation angles for all variables were significant (p < .05), except for the lower trapezius between the 90° and 140° humeral angles. The results of this study suggest assessment of scapular tipping and internal rotation as well as upward rotation may be necessary to understand pathologies of the shoulder that are related to abnormal scapular kinematics.
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Paula M. Ludewig et al.Effects of vibration frequency and postural changes on human responses to seated whole-body vibration exposurehttp://ir.uiowa.edu/oeh_pubs/177
http://ir.uiowa.edu/oeh_pubs/177Wed, 14 Sep 2011 02:36:39 PDT
Abstract â€‚The present investigation evaluated the effects of changes in pelvic orientation and vibration frequency on the seated humanâ€™s response to whole-body vibration (WBV). Seat-to-trunk and seat-to-head acceleration transmissibility, peak-to-peak pelvic motion and erector spinae EMG and mean erector spinae EMG was collected across three pelvic orientations (9 anterior pelvic tilt, neutral pelvis, and 9 posterior pelvic tilt) and frequencies ranging from 4.5 to 16â€…Hz. Subjects included 30 healthy males between the ages of 18 and 35. Ensemble averages, two vibration cycles in length, were produced for each subject within each frequencyâ€“pelvic orientation combination. Group ensemble averages within each frequencyâ€“pelvic orientation combination were then compared using ANOVA. Changes in pelvic orientation produced significant differences in acceleration transmissibility, pelvic motion, and erector spinae EMG. At frequencies below 6â€…Hz, acceleration transmissibility at the head and pelvic motion were significantly greater in the posterior pelvic orientation than in the other two. At frequencies above 6â€…Hz, acceleration transmissibility at the head and trunk were significantly greater in the anterior pelvic orientation than in the other two. Peak-to-peak EMG responses were similar across all pelvic orientations at frequencies below 6â€…Hz. However, above 6â€…Hz, the response was significantly greater in the anterior pelvic orientation than in the other two. Thus, vibration frequency and pelvic orientation were shown to have significant interactive effects on the seated humanâ€™s response to WBV. These interactive effects need to be considered when determining appropriate vibration exposure guidelines.
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Chris L. Zimmermann et al.Effects of Stair-Stepping Exercise Direction and Cadence on Emg Activity of Selected Lower-Extremity Muscle Groupshttp://ir.uiowa.edu/oeh_pubs/176
http://ir.uiowa.edu/oeh_pubs/176Wed, 14 Sep 2011 02:36:37 PDTChris L. Zimmermann et al.Electromyographic Activity of Selected Leg Musculature in Subjects with Normal and Chronically Sprained Ankles Performing on a Baps Boardhttp://ir.uiowa.edu/oeh_pubs/173
http://ir.uiowa.edu/oeh_pubs/173Wed, 14 Sep 2011 02:36:29 PDTGary L. Soderberg et al.Effect of Seat Angle, Lumbar Support, and Foot Rest Height on Ischial Tuberosity Pressurehttp://ir.uiowa.edu/oeh_pubs/172
http://ir.uiowa.edu/oeh_pubs/172Wed, 14 Sep 2011 02:36:27 PDTRichard K. Shields et al.Effect of Seat Angle and Lumbar Support on Seated Buttock Pressurehttp://ir.uiowa.edu/oeh_pubs/171
http://ir.uiowa.edu/oeh_pubs/171Wed, 14 Sep 2011 02:36:25 PDTRichard K. Shields et al.Seat Angles + Support - Replyhttp://ir.uiowa.edu/oeh_pubs/170
http://ir.uiowa.edu/oeh_pubs/170Wed, 14 Sep 2011 02:36:23 PDTRichard K. Shields et al.Lumbar Support Thickness: Effect on Seated Buttock Pressure in Individuals with and without Spinal Cord Injuryhttp://ir.uiowa.edu/oeh_pubs/169
http://ir.uiowa.edu/oeh_pubs/169Wed, 14 Sep 2011 02:36:21 PDTRichard K. Shields et al.Ergonomics: applying what we knowhttp://ir.uiowa.edu/oeh_pubs/168
http://ir.uiowa.edu/oeh_pubs/168Wed, 14 Sep 2011 02:36:19 PDTS. Schneider et al.Effect of pneumatic power tool use on nerve conduction velocity across the wristhttp://ir.uiowa.edu/oeh_pubs/167
http://ir.uiowa.edu/oeh_pubs/167Wed, 14 Sep 2011 02:36:16 PDTJohn C. Rosecrance et al.A comparison of isometric strength and dynamic lifting capacity in men with work-related low back injurieshttp://ir.uiowa.edu/oeh_pubs/165
http://ir.uiowa.edu/oeh_pubs/165Wed, 14 Sep 2011 02:36:11 PDTJohn C. Rosecrance et al.